Cassette supply system to store and handle cassettes and processing apparatus equipped therewith

ABSTRACT

The invention relates to a cassette supply system to store and handle cassettes for substrates and a processing apparatus for processing substrates equipped with said system. The system having a cassette storage provided with base plate constructed and arranged to support cassettes. Also a cassette handler with an end effector with at least one protrusion to support and position the cassette on the end effector is provided to transfer cassettes to and from the base plate. The base plate may be provided with a substantially flat surface to support the cassettes.

FIELD

The invention relates to a cassette supply system to store and handlecassettes for substrates and a processing apparatus equipped therewith.The cassette supply system comprising:

a cassette storage provided with a base plate constructed and arrangedto support cassettes; and,

a cassette handler to transfer cassettes to and from the base plate.

BACKGROUND

When processing substrates such as semiconductor wafers in processingapparatus, the processing apparatus are adapted to and optimized for thesize of the substrate to be processed. The size of the substrates arestandardized in a limited number of discrete sizes where there has beena tendency towards increasing size in the past decennia in order toincrease the production efficiency. The most recently introducedsubstrate sizes are 200 mm and 300 mm diameter. A wafer fabricationfacility will normally be adopted to one substrate size.

To transport the substrates, cassettes may be used which may require aspecific cassette supply system. The cassette supply system may beemployed in the processing apparatus used in the manufacture of discreteand integrated semiconductor products on semiconductor materialsubstrates. The cassette supply system may have a cassette storage witha base plate constructed and arranged to support cassettes to storemultiple cassettes. A cassette handler may be used to transfer cassettesto and from the base plate.

FIG. 1 is a front/bottom perspective view of a cassette 3 having anopening 2 to receive substrates in horizontal slots (not depicted) inthe interior of the cassette. The cassette may be provided with recessessuch as for example the three elongated grooves 7 in the bottom 4 forhandling/positioning of the cassette 3. The ends of the grooves 7 may beclosed as depicted or open ended. The grooves 7 may be constructed by arim extending from the bottom of the cassette 3.

FIG. 2 is a cross-sectional view on a base plate 1 supporting thecassette 3. Plate pins 5 may be provided on the base plate 1 and may bematching with the elongated grooves 7 provided in the bottom of thecassettes 3 to position the cassette 3.

FIG. 3 depicts a top view on the base plate 1, an end effector 9 of acassette handler and the grooves 7 of the cassette during transfer ofthe cassette from the end effector 9 to the base plate 1 or vice versa.As depicted in FIG. 3 the end effector 9 may also be provided with threehandler pins 11 which match with the three grooves 7 provided in thebottom of the cassettes. The cassette may thereby be positioned on theend effector 9 in a predetermined position by the three handler pins 11.

During transfer of the cassette 3 to and from the moveable base plate 1the three grooves 7 in the bottom of the cassette 3 may be in contactwith three plate pins 5 and three handler pins 11 simultaneously. Theposition of the cassette 3 may thereby become overdetermined. Thisoverdetermined position may lead to brusque movements in the transfer ofthe cassette 3 which may lead to particle generation. To alleviate thebrusque movements the end effector 9 may need to move very slowly athigh precision in the transfer of the cassette 3 to and from the baseplate 1 which may deteriorate the throughput of the system and/or leadto a more expensive system.

Accordingly, it may be desirable to provide an improved cassette supplysystem which accommodates an improved transfer of the cassette to andfrom the base plate.

BRIEF SUMMARY OF THE INVENTION

Accordingly, there may be provided a cassette supply system to store andhandle cassettes for substrates. The system may comprise a cassettestorage provided with a base plate constructed and arranged to supportcassettes and a cassette handler to transfer cassettes to and from thebase plate. The cassette handler may comprise an end effector providedwith at least one protrusion to support and position the cassette on theend effector. The base plate may be provided with a substantially flatsurface to support and position the cassettes.

By having a substantially flat surface to support and position thecassettes on the base plate the position of the cassette will not beoverdetermined during transfer of a cassette between the end effectorand the base plate.

A processing apparatus for the manufacture of semiconductor products maybe provided with a cassette supply system in accordance with theinvention. The processing apparatus may further comprise a processingdevice to process substrates and, a substrate handler constructed andarranged to move substrates from a cassette at a substrate load/unloadstation to the processing device and to move the substrates from theprocessing device to a cassette at a substrate load/unload station afterprocessing. The cassette supply system may comprise the cassette handlerconstructed and arranged to transfer cassettes to a substrateload/unload station from the base plate and vice versa. Such an systemmay enable products to be manufactured in large numbers and may be easyto maintain and/or install.

These and other embodiments will become readily apparent to thoseskilled in the art from the following detailed description of certainembodiments having reference to the attached figures, the invention notbeing limited to any particular embodiment(s) disclosed.

BRIEF DESCRIPTION OF THE FIGURES

It will be appreciated that elements in the figures are illustrated forsimplicity and clarity and have not necessarily been drawn to scale. Forexample, the dimensions of some of the elements in the figures may beexaggerated relative to other elements to help improve understanding ofillustrated embodiments of the present disclosure.

FIG. 1 is a front/bottom perspective view of a cassette according to theprior art.

FIG. 2 is a cross-sectional view on a base plate supporting the cassetteaccording to the prior art.

FIG. 3 depicts a top view on the base plate, an end effector of acassette handler and the grooves of a cassette during transfer accordingto the prior art.

FIG. 4 shows, diagrammatically and partially exposed, a perspective viewof a substrate processing apparatus with a cassette supply systemaccording to an embodiment.

FIG. 5 shows a plan view of the substrate processing apparatus of FIG.4.

FIG. 6 depicts a top view on a portion of the base plate, an endeffector of a cassette handler and the grooves of a cassette duringtransfer of the cassette in a cassette supply system in FIG. 4.

FIG. 7 is a cross-sectional view on a portion of a base plate supportingthe cassette in the cassette supply system in FIG. 4.

The figures are not drawn to scale, and particularly the dimensions andthe thickness direction are exaggerated for clarity. Corresponding areasbear the same reference numerals whenever possible.

DETAILED DESCRIPTION

FIG. 4 shows, diagrammatically and partially exposed, a perspectiveview, and FIG. 5 shows a plan view of a substrate processing apparatusfor substrates supplied in cassettes and provided with a cassette supplysystem according to an embodiment. Processing area 21 comprises verticalreactors, and a substrate handling chamber 22 is provided between theprocessing area 21 and a cassette handling area 23 to provide substratesto the reactors. The cassette supply system according to an embodimentis provided in the cassette handling area 23 to transfer and storecassettes 3. An input / output station, to feed or remove cassettes 3into or out of the apparatus, is indicated by 33.

Substrates 13 are supplied in cassettes 3 which may be placed oninput/output station 33. A cassette handler 32 may transfer thecassettes from the input / output station 33 into the cassette store 8located in the cassette handling area 23. This optionally may beaccomplished through a closable opening 34. The cassette store 8 may beprovided with a number of base plates 1 above each other on which thecassettes 3 may be stored. The cassette handler 32 may be provided withan elevator 35 to be movable in a vertical direction, so that many baseplates 1 at different levels may be reached. The cassette handler 32 maybe provided with a cassette end effector 9 may have dimensions a littlesmaller than those of the cut-out 26 in base plate 1. When the cassettehandler 32 has transferred the cassette 3 into the store 8, the endeffector 9 may be lowered through one of the cut-outs 26 in one of thebase plates 1 to place the cassette 3 on said plate. Subsequently, thecassette handler 32 may retract its end effector 9 from cassette store8.

FIG. 6 depicts a top view on cut out portion of the base plate 1, theend effector 9 of the cassette handler 32 and the recesses, e.g.,grooves 7 of the cassette 3 during transfer of the cassette 3 from thecassette handler 32 to the base plate 1 or vice versa. As depicted inFIG. 6, the end effector 9 may be provided with at least a firstprotrusion, which may match with at least a first recess. For example,the three handler pins 11 may match with the three grooves 7 provided inthe bottom of the cassettes 3. The cassette 3 may thereby be supportedand positioned on the end effector 9 with precision.

During transfer of the cassette 3 to and from the moveable base plate 1the rim of the three grooves 7 in the bottom of the cassette 3 may be incontact with a substantially flat surface to support the cassettes 3. Byhaving the substantially flat surface to support and position thecassettes on the base plate 1, the position of the cassette 3 may not beover determined during transfer of the cassette between the end effectorand the base plate 1, making a fast and simple transfer of the cassettepossible.

The flat surface may comprise a flexible material, e.g., rubber toabsorb energy when the cassette is transferred to the surface. Thematerial may have a high friction to keep the cassette on its positionon the flat surface when the base plate 1 is moved.

The base plate 1 may be provided with multiple pads 25 each providedwith the flat surface to support the cassettes. The base plate 1 may beprovided with three pads 25 to support one cassette around one cut out26. One pad 25 may be positioned closer to the center 27 of the baseplate 1. Two other pads 25 may be positioned closer to the edge of thebase plate 1. The pads may be configured on the base plate to match withthe grooves 11 provided in the bottom plate of the cassette 3. The padsmay be configured in a triangular form. The triangular form may beisosceles having at least two edges with the same length or evenequilateral having three edges with the same length.

FIG. 7 is cross-sectional view on a portion of a base plate 1 supportingthe cassette 3. Pads 25 provided on the base plate 1 may be matchingwith the elongated grooves 7 provided in the bottom of the cassettes 3to support the cassette 3. The pads 25 may have a thickness between 1and 10 mm, preferably between 2 and 5 mm to support the cassette 3. Theheight of the base plate 1 and cassette 3 combination may be loweredwith 5 to 20 mm by using pads 25 instead of pins 5 (see FIG. 2) whichmay be advantageously in an system where vertical space may be limitedby the ceiling of the semiconductor manufacturing plant.

The base plate 1 with its pads 25 may be constructed and arranged sothat the flat surface may be the only contact area with the cassette 3.Since the contact area of the pads 25 and the cassette 3 may be largercompared to a situation where pins are used high pressure zones in thematerial may be avoided which makes the design more easy and lesssensitive to wear and/or particle formation.

During transfer of the cassette 3 by the cassette handler 32, the threehandler pins 11 may determine the position of the cassette 3 in thehorizontal plane. The pads 25 allow the positioning of the cassette 3with some play in the horizontal plane. Only in the vertical directionthe pads 25 may function as a hard stop. The flexibility of the materialof the pads 25 however may absorb the energy of the cassettes 3 in thevertical direction so as to make a more quick movements in the transferof the cassette possible while still avoiding particle generation.

The base plate 1 may be provided with visual markings for the positionof the cassette 3 on the base plate 1. An operator, during repairs forexample, may be able to position the cassettes 3 in the correct positionon the base plate with the visual markings such that the cassettehandler 32 may be able to move the end effector 32 in the cut out 26 totake the cassette from the pads 25 with its three handler pins 11.

The cassette handler 32 may be constructed and arranged such that it maybe able not only to transfer cassettes between the input/output station33 and store 8, but that it also may be possible to transfer cassettesbetween store 8 and a rotatable cassette transfer platform 30functioning as a substrate load/unload station and/or betweeninput/output station 33 and the rotatable cassette transfer platform 30.The rotatable cassette transfer platform 30 may be constructed, suchthat on rotation, the cassette 3 may be placed against a partitionbetween cassette handling area 23 and substrate handling chamber 22,which partition may be provided with a closure and a closure mechanism37. After placing the cassette 3 against the closure of the substratehandling chamber 22, the closure mechanism may grip and unlock theclosure of the cassette 3 and may remove the closure of the substratehandling chamber 22 simultaneously with the closure of the cassette 3.The rotatable cassette transfer platform 30 functioning as the substrateload/unload station may comprise at least a first protrusion, e.g.,three pins to support and position the cassette with high precision. Thesubstrate handler 24 may then transfer the substrates from/to thecassette 3 in a smooth manner. The input/output station 33 may compriseat least a first protrusion, e.g., three pins to support and positionthe cassette with high precision as well, so that an Automatic GuidedVehicle or an Overhead Hoist System may automatically place or pick thecassettes from the apparatus for further processing in differentsemiconductor equipment in a semiconductor fabrication plant.

The substrate handler 24 may transfer substrates between the cassetteconcerned and a substrate boat 12. After completion of the loading ofsubstrates into substrate boat 12, arm 16 may move substrate boat 12through a closable opening in the substrate handling chamber 22 intoprocessing chamber 21. Processing chamber 21 may be provided with arotary boat transfer platform 11, supporting the substrate boat 12.

Two reactors 6, which may be heated, may be arranged in the processingchamber 21. The heated reactors may be positioned vertically andsubstrate boats, indicated by 12, filled with substrates 13, may beintroduced into the reactors 6 in the vertical direction from below. Tothis end, each reactor may have an insertion arm 14, which may bemovable in the vertical direction.

The treatment of a large number of substrates may be carried out asfollows. The operator, shown diagrammatically in FIG. 4, may load thestore 8 by introducing a number of cassettes on the input/output stationmanually or with an automated system and carrying out control operationson panel 36. Each of the cassettes 3 may be transferred from the input /output station with the aid of cassette handler 32 into the storagecompartments 31 made for these cassettes 3 in store 8. By rotation ofthe base plate 1 with a moving device around the center of the baseplate 1 and use of the elevator 35, it may be possible to fill variouscompartments 31 with cassettes 3. After filling store 8, no furtherhuman interaction may be required with this automated installation. Thecassettes 3 concerned may then be selected from the store 8 by rotationof the base plate 1 and removed by the cassette handler 32 and placed oncassette transfer platform 30.

The cassette transfer platform 30 may comprise two levels, schematicallyindicated in FIG. 4, each level capable of receiving a cassette. Thelevels may be rotated independently from each other. Upon rotation ofthe cassette transfer platform 30 the cassette may be placed againstclosure 37. After removing the closure of the cassette, together withclosure 37, the substrates may be removed by substrate handler 24 andplaced in substrate boat 12. After the substrate boat 12 has been filledwith substrates it may become available for one of the reactors 6, 7,the closure 19 may be opened and the substrate boat may be placed onrotary boat transfer platform 10. The boat transfer platform then maymove the substrate boat 12 to a position below the reactor 6 to beloaded. Then the insertion mechanism 14 may move the boat into thereactor. Treated substrates may execute a movement counter to the above.

This system is described in further detail in PCT Publication No. WO99/38199 of applicant. Although it is described that an operatorintroduces the cassette on the input/output station, the system isdesigned such that as an alternative the cassettes can be introduced onthe input/output station by means of an automated system, such as anAutomatic Guided Vehicle or by an Overhead Hoist System. In such a case,the control system of the substrate processing system may be connectedto a host computer system that carries out the control functions. Inthis way, no human interaction at the substrate processing system may berequired at all.

The dimensions of the main plate 1 may be adapted to the dimensions ofthe cassette 3, which may be a box-shaped body, with an open front sidewhich may be closed with a closure. The dimensions of the cassette maybe determined by the number and the size of substrates in the cassette.The base plate 1 may have a thickness between 0.2 and 4 mm, preferablybetween 0.3 and 3 mm and may be made from a metal, e.g., steel oraluminum.

The cassette supply system may have a computer operable connected withan optical sensor, such as a camera. The computer provided with aprocessor and a memory, wherein the memory is provided with machinevision software for detecting at least one of a presence and a correctorientation of the substrate cassette on the base plate.

The particular implementations shown and described are illustrative ofthe invention and its best mode and are not intended to otherwise limitthe scope of the aspects and implementations in any way. Indeed, for thesake of brevity, conventional manufacturing, connection, preparation,and other functional aspects of the system may not be described indetail. Furthermore, the connecting lines shown in the various figuresare intended to represent exemplary functional relationships and/orphysical couplings between the various elements. Many alternative oradditional functional relationship or physical connections may bepresent in the practical system, and/or may be absent in someembodiments.

It is to be understood that the configurations and/or approachesdescribed herein are exemplary in nature, and that these specificembodiments or examples are not to be considered in a limiting sense,because numerous variations are possible. The specific routines ormethods described herein may represent one or more of any number ofprocessing strategies. Thus, the various acts illustrated may beperformed in the sequence illustrated, in other sequences, or omitted insome cases.

The subject matter of the present disclosure includes all novel andnonobvious combinations and sub combinations of the various processes,systems, and configurations, and other features, functions, acts, and/orproperties disclosed herein, as well as any and all equivalents thereof.

What is claimed is:
 1. A cassette supply system to store and handlecassettes for substrates, said system comprising: a cassette storageprovided with a base plate constructed and arranged to supportcassettes; and a cassette handler to transfer cassettes to and from thebase plate and provided with an end effector provided with at least oneprotrusion to support and position the cassette on the end effectorwherein the base plate is provided with a substantially flat surface tosupport and position the cassettes.
 2. The system according to claim 1,wherein the flat surface comprises a flexible material to absorb a shockwhen the cassette is transferred to the surface.
 3. The system accordingto claim 1, wherein the flat surface comprises a material with a highfriction to keep the cassette on its position on the flat surface whenthe base plate is moved.
 4. The system according to claim 2, wherein thematerial comprises rubber.
 5. The system according to claim 1, whereinthe base plate is provided with multiple pads each provided with theflat surface to support the cassette.
 6. The system according to claim5, wherein the base plate is provided with three pads to support thecassettes.
 7. The system according to claim 5, wherein the pads toposition and support the cassette have a thickness between 1 and 10 mm,preferably between 2 and 5 mm.
 8. The system according to claim 1,wherein the base plate is provided with a cut out to allow the endeffector to transfer the cassette on the base plate.
 9. The systemaccording to claim 1, wherein the base plate is constructed and arrangedso that the flat surface is the only contact area with a cassettesupported thereon.
 10. The system according to claim 1, wherein the baseplate is provided with visual markings for the position of the cassetteon the base plate.
 11. The system according to claim 1, wherein thesystem comprises a moving device constructed and arranged to move thebase plate with respect to the cassette handler.
 12. The systemaccording to claim 1, wherein the system comprises an input/outputstation for receiving cassettes and the cassette handler is constructedand arranged to transfer cassettes from the input/output station to themoveable base plate and vice versa.
 13. The system according to claim12, wherein the input/output station comprises at least a firstprotrusion to position the cassette with high precision on theinput/output station.
 14. The system according to claim 1, wherein thesystem comprises a substrate load/unload station for receiving cassettesand the cassette handler is constructed and arranged to transfercassettes from the load/unload station to the base plate and vice versa.15. The system according to claim 14, wherein the substrate load/unloadstation comprises at least a first protrusion to position the cassettewith high precision on the substrate load/unload station.
 16. The systemaccording to claim 1, wherein the baseplate has a horizontal plane toreceive the cassettes and the system is constructed and arranged withthe baseplate rotatable around a vertical axis.
 17. The system accordingto claim 1, wherein the system is provided with a sensor to detect atleast one of the presence and the correct orientation of the cassetteson the base plate.
 18. The system according to claim 17, wherein thesystem is provided with a computer operable connected with the sensorand provided with a processor and a memory, wherein the memory isprovided with machine vision software for detecting at least one of thepresence and the correct orientation of the cassettes on the base plate.19. A processing apparatus for processing substrates comprising: aprocessing device to process substrates; a substrate handler constructedand arranged to move substrates from a cassette at a substrateload/unload station to the processing device and to move the substratesfrom the processing device to a cassette at a substrate load/unloadstation after processing; and a cassette supply system to store andhandle cassettes according to claim 1 and the cassette handler isconstructed and arranged to transfer cassettes to a substrateload/unload station from the base plate and vice versa.
 20. Theprocessing apparatus for processing substrates according to claim 19,wherein the processing device comprises a reactor with a reactionchamber for processing a plurality of substrates.